In a parallel hybrid power transmission mechanism combining a motor generator and an engine, a motive power is transmitted by jointing a crank shaft of an engine, a rotor of a motor generator, an input shaft of a passive movement device in sequence as shown in patent documents 1 and 2. In this manner, (1) a motive power of the engine is transmitted to the passive movement device through the rotor of the motor generator, (2) a motive power of the motor generator is transmitted directly from the rotor to the passive movement device, and thus the motive powers of two systems both are transmitted through the rotor of the motor generator.
In addition, a clutch device is arranged between the engine and the passive movement device, and the arrangement thereby absorbs the torsional vibration generated depending on a relation between the engine and the passive movement device and thus smoothly transmits the motive power.